A. Related Applications
There are no applications related hereto heretofore filed in this or any foreign country.
B. Field of Invention
My invention provides an instrument to measure the gaseous products of metabolism of several microbal samples and particularly the volume of gas, as a function of time, produced by yeast fermentation.
C. Description of Prior Art
My invention is concerned generally with the measurement of gases produced by microbal metabolism and especially carbon dioxide produced in the yeast-flour fermentative process. This type of measuration is particularly important in materials testing and in determining process parameters in processes involving yeast, such as brewing and yeast production, as well as general microbal processes that produce gas.
Yeast metabolism, whether of the respiratory or fermentative type, produces carbon dioxide and commonly this is the only gaseous product of the metabolism, at least that is produced in any significant quantity. Because of this reaction a common method of measuring yeast activity has been to measure the volume of gas produced by a particular sample under pre-determined conditions over a period of time. This measure may then be used either absolutely or comparatively to determine the activity of the particular yeast or the nature of other process components or parameters. The common method of making this measuration in the past has been to use a typical laboratory bomb with an attached manometer of some sort. The process has been individualistic by nature, quite time consuming, a clumsy operation and generally has provided no automatic record of gas production as a function of time. The results oftentimes from tests made at different times have not been particularly constant or repeatable, apparently principally because of inconsistencies and inaccuracies that resulted from the laboratory nature of the process.
My invention seeks to solve these problems by providing a testing apparatus to record the gas production of individual microbal samples as a function of time. The testing apparatus may be adapted by combining sample modules to operate simultaneously on a plurality of samples. It provides a hydraulically activated recording mechanism that creates a continuous record of total volume of gas production over a period of time while former devices measured only such gas production at one or more discrete points of time. The record is commonly provided on paper by differentiable recording pens so that the trace from each sample may be readily distinguishable from that of another. The device provides temperature controls to maintain appropriate thermal environment for samples and does not raise gas pressure on the sample any more than would a normal vented manometer. The results obtained with the apparatus are substantially similar to those obtained with the non-recording bombs heretofore used for such purposes, but are quite consistent and repeatable.